meyer



Jan. 31, 1956 E. A. MEYER 7 ELASTIC CASCADING IMPACT ABSORBER Filed June 15, 1953 2 Sheets-Sheet l w flaw WM INVENTOR. EARL A. MEYER lay/4Q Attorney E. A. MEYER ELASTIC CASCADING IMPACT ABSORBER Jan. 31, 1956 2 Sheets-Sheet 2 Filed June 15, 1953 3 wry/dug INVENTOR. EARL A. MEYER BY %4 q. 224/ Ahomey United States Patent thee 2,733,177 Patented Jan. 31, 1956 Earl A. Meyer, Madison, Wis, assignor to lijo search Laboratories, Inc, a corporation oi Application June 15, 1353, Serial No. 361,72)

17 Claims. (Ci. 154--S2.5)

This invention relates to armor and more PZll'llC. irly to armor of the type which may 1.. x am by ind personnel and which must absorb the impact of p: tiles such as rifle bullets.

in order to ha e an efficient impact r is required in personal armor, it is essential that the force of an impinging projectile be distributed over as large an area as possible. This has been done heretofore by causing the projectile to be mashed or squashed in the outer layers of the armor, or by deflecting the projectile sidewise so that it presents a large cross-section toward the armor.

This application is a continuation-impart application of my application Serial No. 306,088, filed August 25, 1952, having the same title.

it is obvious, of course, that armor should be as light as possible, and it is desirable that the armor not depend for its operability upon the softness of the projectile; it should not be subject to the limitation that it will operate only if the projectile is soft enough to mash or squash sufiiciently.

It is therefore an object of this invention to provide an impact-absorbing armor, suitable for use by individual personnel and mobile vehicles, which is light in weight and yet will prevent passage therethrough of high velocity impinging projectiles.

Another object is such a device composed of a plurality of layers of rigid plates and elastic layers adapted to provide elastic separation of said layers of plates.

Further objects will become apparent from the drawings and the following detailed description in which it is my intention clearly to set forth and describe my invention and to show its applicability without limiting its scope. In the drawings and description like reference numerals refer to like parts.

Figure 1 is a partially cut away perspective view from above of a portion of the armor of my invention;

Figure 2 is a perspective view of a portion of an elastic layer comprising a sheet having springs stamped out therefrom, adapted to provide elastic separating means between the layers of rigid plates in the armor assembly as shown in Figure 1;

Figure 3 is a cross-sectional view of the sheet shown in Figure 2 taken along lines 3-3;

Figure 4 is a perspective view of a portion of another embodiment of an elastic layer comprising a sheet having springs stamped out therefrom adapted to provide elastic separating means between the layers of rigid plates in the armor assembly;

Figure 5 is a cross-sectional view of an armor assembly utilizing the elastic layer shown in Figure 4;

Figure 6 is a perspective view of a portion of another embodiment of an elastic layer;

Figure 7 is a cross-sectional view of the armor assembly utilizing the elastic layer shown in Figure 6;

Figure 8 is a perspective view of another embodiment of an elastic layer;

Figure 9 is a cross-sectional view of the armor assembly utilizing the elastic layer shown in Figure 8;

Figure 10 is a perspective view of a portion of another embodiment of an elastic layer comprising a sheet of material having springs stamped out therefrom adapted t provide elastic separating means between layers of etal sheets in the armor assembly;

g 11 is a cross-sectional view of the armor assembly aiming he layer shown in Figure 10;

Figure 12 is a crosssectional view of one embodiment of the armor structure in which synthetic resin fills the interstices of the structure.

R ferring now to Figure 1, there is shown a portion nor consisting of three layers of rigid plates respec- 1 and 5 and laminated thereinbetween and adapted to elastically support and separate layers 3 and 5. The layers may be attached to each other by means of adhesives or welding or by a combination these methods or by other means known to the art. The elements of the armor may also be attached as shown in Figure 12. Layer 1 is composed of rigid plates such as plate 7 which has all of its edges in abutting relation to adjacent plates, and which may be composed of metal or of glass-fabric reinforced plastic. The plates in layer 1 are preferably square as shown but may be certain other shapes as describedin application Serial No. 306,088, filed August 25, 1952. The plates in layer 1 such as plate 7 must be small enough, hard enough, and rigid enough so that when struck by aprojectile, each will not be pierced by the bullet but will move as a unit with the bullet. Therefore, the plates may suitably be about /2 in width to about 6" in width and may be from about .005" thickness to about 1" thickness. Plates of layer 1 may be adhesively or thermally welded or attached to elastic layer 2 which may be composed of a sheet 12 and springs 13 stamped out therefrom.

As shown in Figures 1, 2 and 3, sheet 12 may be of an elastic material such as steel having a spring constant selected so that the plates of layer 1 will compress springs 13 stamped out from sheet 12 when struck by a projectile, compressing layer 2 and transmitting force to layer 3, at the same time slowing down the projectile and converting a certain portion of its energy from kinetic to potential energy stored in the compressed material. It may be seen that springs 13 are cantilever springs. Below layer 2 and attached thereto is a layer 3 composed of rigid plates such as plate 8, with edges abutting those of adjacent plates. Each of the plates in layer 3 such as 8 has a surface area larger than that of each of the plates such as 7 in layer 1, and the plates of layer 3 are so arranged that the junctions at their edges or joints, such as joint 9 between plate 8 and an adjoining plate, do not fall directly below any of the joints in layer 1. by making the plates such as 8 have four times the area of the plates such as 7, where the plates are square, this may be accomplished with ease. The plates of layer 3 may be either thinner or thicker than those of layer 1 and may have a higher or lower spring constant. Since the force of the projectile is transmitted to these plates by the relatively large area of one or more of plates such as 7, as compared with the relatively small area presented by the nose of a bullet, it is not so necessary that plates such as 8 be of a material which will resist puncture as it is desirable that they be of such a material that they will not be torn apart or so severely bent that they will fail to transmit force to the next layer below through almost the entire area on the lower surface of each plate. Elastic layer 4 below layer 3 may be composed of a sheet 12 and springs 13 stamped out thereed thereto, three elastic layers, respectively 2, 4/

from. cheet 12 may be of an elastic material such as steel having a spring constant which may be different from that o layer 2; for example, it may be selected to deform less than layer 2 and convert and store more energy in so deforming. Layer 4 may be identical in form to layer 2 (as shown) or may comprise springs having a different size or shape than springs 13. Below layer 4 and attached thereto is another layer of rigid plates 5. Layer 5 is composed of rigid plates which may be square as shown, such as plate 10. if square plates are used, each of the plates such as preferably has a surface area four times greater than the plates such as S in the next layer 3 of plates above and the plates are so arranged that the joints thereinbetween such as 11 do not fall directly below and parallel to the joints in layer 3. Below layer 5 is another layer 6 of elastic material attached to the plates of layer 5. Materials of layers 5 and 6 are selected to have spring constants which will provide a maximum of energy con version or storage with a minimum of deformation. and serve as the final protection for the protected structure. It will, of course, be understood that the invention may be operable with either more layers or less layers than shown such as two layers of rigid plates and two elastic layers or four or five layers each of rigid plates and elastic layers, except that two layers of each kind is the minimum with which the invention is operable.

Thus the force of the projectile is distributed over a large area by a series of cascading rigid plates of regularly increasing size, connected together by elastic layers of selected spring constants, and the area through which force is transmitted to the next adjacent layer of plates is increased by a regular factor such as four for each succeeding layer.

To minimize the impact on the structure protected by the armor it is desirable that the process of absorbing the energy of the bullet be spread out over as long a duration as possible. This is accomplished by the layers 2, 4 and 6. The spring constants of these several layers may be equal or may be varied at will but it is believed best that the outermost elastic layer such as layer 2, have the lowest spring constant in order that the relatively small rigid plates which come into direct contact with the projectile shall each move as a unit, since these plates must not be pierced by the bullet if the structure is to work efficiently. The spring constant of the elastic layer next below, such as layer 4, should generally be greater than that of layer 2 in order to absorb more energy, more effectively to delay the transmittal of that energy to the next adjacent layer below, and more efiicicntly to distribute the energy of the bullet over the widest possible area in the next layer of plates below. Thus the elastic layer next adjacent the supporting and protected structure, such as layer 6, should generally have the highest spring constant of the several elastic layers. By grading the spring constants in this manner, the outermost elastic layer, such as layer 2, may be almost completely compressed before the next layers below such as layers 4 and 6 become compressed appreciably. Thus the forward motion of the projectile is halted over a maximum length of time, the rate of energy absorption increasing as the energy is transmitted through the layers of the armor and as the energy remaining to be absorbed decreases.

As a result of the conversion of the kinetic energy of the bullet to stored potential energy in the compressed layers of elastic material, the stored energy is immediately available for reconversion into kinetic energy. This reco-nvcrsion begins at the moment the bullet ceases to travel forward, the bullet being accelerated in a reverse direction. Because a large proportion of the energy which the bullet: had at the moment of striking is stored in the compressed elastic layers and because the conversion and storage is relatively eiiicient, a large portion of the energy which the bullet has upon striking the armor may be returned to it and therefore it may be ejected outwardly from the armor with considerable force.

The spring constant of elastic layers, such as layers 2, 4 and 6, may be varied by any one of several means.

For example, the spring constant of one layer may be made different from another layer by varying the spring constant of the steel or other material of which plates 12 having cantilever springs 13 stamped out therefrom are made. The spring constant may also be varied by changing the size or the shape of the springs i3 stamped out from plates 12. The spring constant may also be varied by varying the thickness of the material oi? which plates 12 and springs 13 are made. Thus the spring constants of layers 2, 4 and 6 may be progressively increased by progressively increasing the thickness of the material of which plates 12 and springs 13 are made. Any one or more of these changes may be made to provide layers 2, 4 and 6 of different spring constants instead of providing layers 2, 4 and 6 oi equal spring constants as illustrated in Figure 1.

Referring now to Figures 4 and 5, layers 2, 3 and 5 comprise rigid plates having edges abutting one to another and having a regular progression in size of the plates respectively in layers 1, 3 and 5. Joints in one layer of plates do not lie below and parallel to joints in another layer. These layers are separated by (and layer 5 is supported by) elastic layers 22, 24 and 26. Elastic layer 22 consists of a sheet 27 of elastic material such as steel, having cantilever springs 28 stamped out therefrom. Elastic layers 24 and 26 may be similar, but as shown are more massive being similar in form to layer 22 but having larger and heavier springs stamped out of thicker sheets 27' and 27" respectively.

Referring now to Figures 6 and 7 there is shown another embodiment wherein elastic layers 32, 34 and 36 support and separate layers of rigid plates 1, 3 and 5. Layers 1, 3 and 5 may have the characteristics described hereinbefore and in application Serial No. 306,088, filed August 25, 1952. Elastic layer 32 may consist of springs 38 stamped out from one or more sheets of elastic material in such manner that all of the material in the sheets is utilized to form springs. It may be seen that the springs 38 are provided by wavy or undulating strips such as 37 and 37'. Each of these strips may constitute a separate sheet (strip-like in form) prior to stamping out the springs or the springs may be stamped out from a single large sheet, in which event they may remain attached to one another at points of adjacency such as 39 and 39'. Springs 38, as shown, are semi-elliptical in form, and adjacent springs extend in opposite directions from one another. Thus, each pair of springs is adapted to function substantially as a full elliptical spring. Elastic layers 34 and 36 may be identical with layer 32 or may (as shown) be similar to layer 32 in form but of progressively greater thickness and size, having larger springs stamped out from a plate of greater thickness.

Referring now to Figures 8 and 9 there is shown another embodiment wherein elastic layers 42, 44 and 46 support and separate layers 1, 3 and 5 of rigid plates. Layers 1, 3 and 5 may be provided as described hereinabove. Layer 42 may consist of a sheet 47 of elastic material such as steel having semi-elliptical springs 48 stamped out therefrom. Because adjacent springs extend in opposite directions, each part of springs 48 is adapted to function as a full elliptical spring. Layers 44 and 46 may be identical with layer 42 or may, as shown, be similar in form to layer 42 but have larger springs stamped out from a sheet of elastic material.

As shown in Figures 10 and 11, elastic layers 52, 54 and 56 may separate and support layers 1, 3 and 5 of rigid plates, which may be provided as described hereinbefore. Layer 52 may consist of a sheet 57 of elastic material such as steel having springs 58 stamped out therefrom. Springs 58 may be semi-elliptical in form and may extend upwardly or may extend downwardly as shown at 58. Strips 59 between springs 58 may be bent in a plane normal to the plane in which springs 58 are bent and may thus provide a resilient mounting, comparable to that of spring shackles, for the springing action of semi-elliptical springs 58. Layers 54 and 56 may be similar to layer 52 but the springs therein may be larger.

it may be seen that there is no critical requirement as to the form of springs which may be utilized. The invention relates broadly to providing an armor assembly comprising layers of rigid plates, as described in copending application Serial No. 306,088, filed August 25, 1952, supported and separated by elastic layers each of which comprises a plurality of small springs stamped out from a sheet of elastic material such as steel. The springs may have any one of a large number of forms and need not be connected one to another (see Figures 6 and 7). The most important requirement for the springs is that they be suificiently small that each plate in each layer is supported by a relatively large number of springs.

An important advantage of the elastic layers of the invention is that those which are made of a preferable material, that is of a metal alloy, are non-flammable and therefore not susceptible to the initiation or suste- ..c of :1 fire in the armor structure which might otherwise be caused by military weapons such as exploding projectiles, jcllicd gasoline and the like.

The rigid plates may have the shape of squares, rectangles, hexagons, triangles, parallelograms, or crescents, but generally it is preferable that all the rigid plates in a single armor structure have substantially the same shape. The ratio between the area of each of the rigid plates in one layer and the area of each of the rigid plates in the next layer may be i to 2, or may be 1 to 4, or may be 1 to 9, or may be 1 to 3.2. Thus, ratios between areas of each plate in three layers of rigid plates may be 1:2:4; 1:4.- l6; l:3.2:l; 1:9:81, or any other suitable regular pro ssion. Generally a ratio of 1:4:l6 is preferable.

it is a characteristic of the armor of the invention that the rigid plates in each of the layers have their edges abutting so there no space between plates in any single layer. it is also an important characteristic of the armor of the invention that no joint between any two plates in any layer lies directly above or below and parallel to any joint between plates in any adjacent layer.

The rigid plates of the invention may be made of any one of a large group of materials. Laminates of glass fabric impregnated with polyester resins and glass fiber filled polyester and urea formaldehyde and melamine formaldehyde resins have been found particularly suitable but preferable materials include any thermosetting synthetic resin such as polyester resins and urea-melamine and phenol-formaldehyde resins filled or otherwise reinforced with glass fibers in either mat or fabric form or with other fibrous materials such as canvas. Other materials are also suitable such as, for example, any one 1 number of hard armor plate alloys. A lighter armor lx ..t.nicved with the preferred resinous materials but such lard oys which may be used include alloys comprising cobalt, chromium and tungsten (sold as Stellites) alloys such as nickel, cobalt, manganese and chromium-steels comprising a relatively large percentage of iron, or an alloy of 60% nickel, 20% chromium, 10% iron, 1.75% ma: anese and .5 carbon sold as fire armor."

The material of which the springs in the elastic layers is made may be any material suitable for making springs such as a spring steel, a spring brass, a spring bronze, at beryllium alloy, :1 copper alloy and the like. It is generally preferable that the material be a metal alloy.

n Figure 12 there is shown layers 1, 3 and of rigid es, supported and separated by elastic layers 32', 34' 36', comprising springs 38'. These several elements l plat nd are attached together by synthetic resin 44 which permeates the Whole structure.

Synthetic resin 40 may be any suitable synthetic resin which is flexible or which is both elastic and flexible. It may be applied by immersing the entire structure in polymerizable mat rial and then polymerizing said material to provide synthetic resin 4h. utiliting any one of the techniques generally ltnown as potting. The resin may be polymerized at either room temperature or elevated temperature. The armor and the resin may be mained at s atmospheric pressure or super-atmospheric pressure during polymerization. Resins which may be used for this purpose include. for example, styrenated polyesters, epoxy resins, vinyl plastisols, acrylic resins such as polymers or copolyi s comprising methacrylic acid, acrylic acid, ethyl acrylate, propyl acrylate, butylnnd high-carbon nlltyl methacrylates, butyland higher carbon alityl acrylates, and these same resins in formed form, especially foamed epoxy resins and foamed poly ester resins, and also foamed cellulose ethers and esters, foamed latex and the like.

it will thus be seen that the invention is broad in scope and I wish it to be understood that my invention is not to be limited to specific herein described and shown.

Having thus disclosed my invention, I claim:

l. Armor adapted to restrain penetration of projectiles therethrough, comprising layers of rigid plates having laminated tl'tcreinbctween elastic layers each of which nprises a plurality of sprin and means for holding said layers together, each of id layers of rigid plates comprising plates having edges abutting.

2. Armor adapted to restrain penetration of projectiles therethrough comprising layers of rigid plates having laminated thereinbctween elastic layers each of whichcomprises a plurality of leaf springs, and means for holdlug said layers together. each of said layers of rigid plates comprising plates having cdgcs abutting, each of the plates in each of said lay of rigid plates naving an area greater than the area of each of the plates in the next above layer of rigid plates.

3. Armor adapted to restrain penetration of projectiles therethrough, comprising layers of rigid plates havlug laminated thercinbetwcen elastic layers each comprising a plurality of leaf sprin stamped out from a sheet of elastic material, and means for holding said layers together, each of the plates in each of said layers of rigid plates having an area greater than the area of each of the plates in the next above layer of rigid plates and the plates in each layer being so arranged that no joint between any we plates is superin'iposcti directly above and parallel with any joint in any next adjacc t layer of rigid plates.

4. Armor adapted to restrain penetration of projectiles therethrough, compt'sing layers of rigid plates having laminated thereinl' eiween elastic layers each comprising a plurality of leaf springs stamped out om a sheet of elastic material. and means for holding said layers together, each of the plates in each of said layers of 1' plates having an area at least two times as great as th area of each of the plates in the nest :1 ove layer of 1' plate.

5. The armor of claim 4 in which said springs are cantilever in type, being free from said plate at one end.

6. The armor of claim 4 in which each of said springs is semi-elliptical.

7. The armor of claim 4 in which each of said springs is semi-elliptical and adjacent springs project oppositely, the springs thereby being adapted to function as full elliptical springs.

8. The armor of claim 4 in which the area relationship between each of the plates in one of said layers of rigid plates and each of the plates in the next adjacent layer of rigid plates is 1:4.

9. The armor of claim 4 in which the area relationn or arrangement ol parts 7 ship between each of the plates in one of said layers of rigid plates and each of the plates in the next adjacent layer of rigid plates is substantially 1:32.

10. Armor adapted to restrain penetration of projectiles therethrough and adapted to be worn by individuals, comprising layers of rigid plates having laminated thereinbetween layers of stamped out leaf springs, and means for holding said layers together, each of said layers of rigid plates comprising plates of identical shape having edges abutting, each of the plates in each of said layers of rigid plates having an area at least two times as great as the area of each of the plates in the next above layer of rigid plates and the plates in each layer being so arranged that no joint between any two plates is supcrimposed directly above and parallel with any joint in any next adjacent layer of rigid plates.

ll. Armor adapted to restrain penetration of projectiles therethrough comprising a layer ot" rigid plates, an elastic layer next adjacent below attached thereto, said elastic layer comprising a plurality of springs, a second layer of rigid plates below and attached to said elastic layer, each of the plates of said layer having an area at least two times greater than the area of each of the plates in the first layer and so arranged that none of the joints between plates in the second layer are directly below and parallel with any joint between plates in the first layer. and an elastic layer comprising a plurality of springs below said second layer of plates attached thereto, and means for holding said layers together.

12. The armor of claim 11 in which said springs are leaf springs stamped out front a metal sheet.

13. The armor of claim 12 in which each of said springs is a cantilever spring.

14. The armor of claim 12 in which each of said springs is a semi-elliptical spring.

15. The armor of claim 12 in which each of said springs is semi-elliptical and adjacent springs project oppositely, said springs being adapted to function as full elliptical springs.

16. The armor of claim 11 in which the area relationship between' each of the plates in one of said layers of rigid plates and each of the plates in the next adjacent said layer of rigid plates is substantially 123.2.

17. Armor adapted to restrain penetration of pro ectiles therethrough comprising a layer of rigid plates elastic layer next adjacent below attached theretr. elastic layer comprising a plurality of leaf springs stamped out from a metal sheet, a second layer of r identical shape below it attached to said each of the plates of said layer having an a two times greater than the area of each of the the first layer and so arranged that none of the joints between plates in the second layer are directly below and parallel with any joint between 57% es in the first layer, and a second elastic layer below d second layer of plates and attached thereto, said so d clitstic layer comprising a plurality of lealsprings stamped out fro l a metal sheet, and means for holding said layers together.

References Cited in the file of this patent UNITED STATES PATENTS 1,290,799 Talley lati. 7. 1919 l,296,ll3 Perlman s. s Mar. 4, i919 l,758,296 Schaumann May 13, i930 2,399,184 Heckert Apr. 30, 1946 FOREIGN PATENTS 19,360 Great Britain 1913 854,059 France Jan. 2, i940 

2. ARMOR ADAPTED TO RESTRAIN PENETRATION OF PROJECTILES THERETHROUGH COMPRISING LAYERS OF RIGID PLATES HAVING LAMINATED THEREBETWEEN ELASTIC LAYERS EACH OF WHICH COMPRISES A PLURALITY OF LEAF SPRINGS, AND MEANS FOR HOLDING SAID LAYERS TOGETHER, EACH OF SAID LAYERS OF RIGID PLATES COMPRISING PLATES HAVING EDGES ABUTTING, EACH OF THE PLATES IN EACH OF SAID LAYERS OF RIGID PLATES HAVING AN AREA GREATER THAN THE AREA OF EACH OF THE PLATES IN THE NEXT ABOVE LAYER OF RIGID PLATES. 